كتاب 2
2  
Book 2
(2)
Chapter 2
(2)
باب 2
Muwatta Malik 128
Yahya related to me from Malik that he had heard that Salim ibn Abdullah and Sulayman ibn Yasar were asked whether the husband of a menstruating woman could have sexual intercourse with her when she saw that she was pure but before she had had a ghusl. They said, "No, not until she has had a ghusl."
وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّ سَالِمَ بْنَ عَبْدِ اللَّهِ، وَسُلَيْمَانَ بْنَ يَسَارٍ، سُئِلاَ عَنِ الْحَائِضِ، هَلْ يُصِيبُهَا زَوْجُهَا إِذَا رَأَتِ الطُّهْرَ قَبْلَ أَنْ تَغْتَسِلَ فَقَالاَ لاَ حَتَّى تَغْتَسِلَ ‏.‏
Reference : Muwatta Malik 128
In-book reference : Book 2, Hadith 34306
USC-MSA web (English) reference : Book 7, Hadith 128
  (deprecated numbering scheme)